Systems and methods for substrate support temperature control

ABSTRACT

Exemplary temperature modulation methods may include delivering a gas through a purge line extending within a substrate support. The gas may be directed to a backside surface of the substrate support opposite a substrate support surface. The purge line may extend along a central axis of a shaft, the shaft being hermetically sealed with the substrate support. The substrate support may be characterized by a center and a circumferential edge. A first end of the purge line may be fixed at a first distance from the backside surface of the substrate support. The methods may include flowing the gas at a first flow rate via a flow pathway to remove heat from the substrate support to achieve a desired substrate support temperature profile.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. patentapplication Ser. No. 62/930,249 filed Nov. 4, 2019, the contents ofwhich are hereby incorporated by reference in their entirety for allpurposes.

TECHNICAL FIELD

The present technology relates to semiconductor deposition processes.More specifically, the present technology relates to systems and methodsfor modulating temperature profiles for substrate supports.

BACKGROUND

Integrated circuits are made possible by processes which produceintricately patterned material layers on substrate surfaces. Producingpatterned material on a substrate requires controlled methods offormation and removal of exposed material. As device sizes continue toshrink, material uniformity may affect subsequent operations. Forexample, the temperature non-uniformity of a substrate heater may affectsubsequent deposition film thickness uniformity.

Thus, there is a need for improved systems and methods that can be usedto produce high quality devices and structures. These and other needsare addressed by the present technology.

SUMMARY

Exemplary temperature modulation methods may include delivering a gasthrough a purge line extending within a substrate support. The gas maybe directed to a backside surface of the substrate support opposite asubstrate support surface. The purge line may extend along a centralaxis of a shaft, the shaft being hermetically sealed with the substratesupport. The substrate support may be characterized by a center and acircumferential edge. A first end of the purge line may be fixed at afirst distance from the backside surface of the substrate support. Themethods may include flowing the gas at a first flow rate via a flowpathway to remove heat from the substrate support to achieve a desiredsubstrate support temperature profile.

In some embodiments, the flowing may include increasing the first flowrate to a second flow rate to decrease a temperature of the substratesupport temperature profile. In some embodiments, the flowing mayinclude decreasing the first flow rate to a second flow rate to increasea temperature of the substrate support temperature profile. Deliveringthe gas may include delivering the gas through a nozzle at the first endof the purge line. The nozzle may be configured to direct the gas to afirst portion of the backside surface of the substrate support.

The first portion may be characterized by a first diameter. The nozzlemay be adjustable to a second diameter to direct gas to a second portionof the backside surface of the substrate support. The second portion maybe characterized by a second diameter. The second diameter may bedifferent than the first diameter. A substrate support temperature maymaintained above or about 100° C. during a semiconductor process. Thedesired substrate support temperature profile may include a uniformtemperature range deviating by at most about 1 degree Celsius at acentral location during a semiconductor process. The first end of thepurge line may be fixed at the first distance from the backside surfaceof the substrate support with a bracket. The first distance may be atmost about 3 mm. The gas may be a high thermal conductivity gas. The gasmay be chosen from at least one of helium, nitrogen, argon, andcombinations thereof. Delivering the gas may include supplying the gasto the purge line at room temperature. Delivering the gas may includesupplying a preheated gas to the purge line.

Some embodiments of the present technology may encompass a semiconductorprocessing chamber. The semiconductor processing chamber may include asubstrate support. The substrate support may have a substrate supportsurface for contacting a substrate. The substrate support may becharacterized by a central axis through the substrate support, abackside surface opposite the substrate support surface, and acircumferential edge connecting the substrate support surface and thebackside surface. The substrate support may be disposed within aprocessing region of the semiconductor processing chamber. Thesemiconductor processing chamber may include a shaft about the centralaxis and hermetically sealed with the backside surface of the substratesupport. The semiconductor processing chamber may include a purge linedisposed concentrically within the shaft and about the central axis. Thepurge line may have a nozzle at a first end fixed at a first distancefrom the backside surface of the substrate support. The nozzle may beconfigured to deliver a high thermal conductivity gas to a first portionof the backside surface of the substrate support. The first portion maybe characterized by a first diameter. The semiconductor processingchamber may include a flow pathway for convectively contacting thesubstrate support with the high thermal conductivity gas. The highthermal conductivity gas may be exhausted through the shaft to removeheat.

In some embodiments, the semiconductor processing chamber may include atleast one of an RF line and an AC line. The nozzle may be adjustable todeliver the high thermal conductivity gas to a second portion of thebackside surface of the substrate support. The second portion may becharacterized by a second diameter. The second diameter may be differentthan the first diameter. The semiconductor processing chamber mayinclude a gas supply configured to adjust the flow rate of the highthermal conductivity gas. The semiconductor processing chamber mayinclude a thermocouple disposed within the purge line. The purge linemay include a flexible material or a rigid material. The purge line mayinclude a material chosen from stainless steel, aluminum, nylon, orcombinations thereof. The substrate support may be or include a ceramicmaterial. In some embodiments, the substrate support may be or includealuminum nitride.

Such technology may provide numerous benefits over conventional systemsand techniques. For example, the processes may produce a substratesupport characterized by a controlled temperature profile. Additionally,the operations of embodiments of the present technology may producefilms characterized by a more uniform thickness. These and otherembodiments, along with many of their advantages and features, aredescribed in more detail in conjunction with the below description andattached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the disclosedtechnology may be realized by reference to the remaining portions of thespecification and the drawings.

FIG. 1 shows a schematic cross-sectional view of an exemplary processingchamber according to some embodiments of the present technology.

FIG. 2 shows exemplary operations in a temperature modulation methodaccording to some embodiments of the present technology.

FIG. 3 shows a schematic view of a substrate support and shaft includinga purge line according to some embodiments of the present technology.

FIG. 4 shows a plot of film thickness using a conventional substratesupport having a non-uniform temperature profile.

FIGS. 5A-5E show schematic views of exemplary temperature profiles forsubstrate supports according to some embodiments of the presenttechnology.

Several of the figures are included as schematics. It is to beunderstood that the figures are for illustrative purposes, and are notto be considered of scale unless specifically stated to be of scale.Additionally, as schematics, the figures are provided to aidcomprehension and may not include all aspects or information compared torealistic representations, and may include exaggerated material forillustrative purposes.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a letter thatdistinguishes among the similar components. If only the first referencelabel is used in the specification, the description is applicable to anyone of the similar components having the same first reference labelirrespective of the letter.

DETAILED DESCRIPTION

During semiconductor fabrication, structures may be produced on asubstrate utilizing a variety of deposition and etching operations. Asubstrate support may hold and heat the substrate for processing. Thesubstrate support may be embedded with heating elements. Due to at leastone of the substrate support construction, the substrate supportmaterials, the heating elements, and the heating element design, anon-uniform temperature profile in the substrate support may result andlead to a substrate being deposited with a non-uniform film thicknessduring a deposition operation. For example, the substrate supportmaterials, which may be a ceramic material such as aluminum nitride, mayhave non-uniform sintering during manufacture causing densitynon-uniformity from the center to the edge of the circular substratesupport. As device sizes continue to reduce and film thicknesses onsemiconductor substrates are on the nanometer scale or less, even smalltemperature differences within the substrate from the substrate supportmay influence film deposition onto the substrate. For example,temperature differences may be on the order of only a few degrees, suchas less than five degrees Celsius or less, to have a deleterious effecton film thickness uniformity.

The present technology may overcome these limitations by modulating thetemperature profile of the substrate support to provide a desiredtemperature profile for a substrate during the deposition. For example,the present technology may include providing a purge line within apedestal shaft holding a substrate support to flow a gas directed to thesubstrate support during deposition. This may facilitate a more uniformtemperature profile or a more controlled temperature profile, which mayreduce or limit film thickness non-uniformity during deposition.Additionally, by controlling temperature at specific locations withinthe pedestal, such as at a center location, deposition characteristics,such as increased central deposition, may be better controlled. Afterdescribing general aspects of a chamber according to embodiments of thepresent technology in which plasma processing operations discussed belowmay be performed, specific methodology and component configurations maybe discussed. It is to be understood that the present technology is notintended to be limited to the specific components and processingdiscussed, as the techniques described may be used to improve a numberof film formation or removal processes, and may be applicable to avariety of processing chambers and operations.

FIG. 1 shows a cross-sectional view of an exemplary processing chamber100 according to some embodiments of the present technology. The figuremay illustrate an overview of a system incorporating one or more aspectsof the present technology, and/or which may perform one or moreoperations according to embodiments of the present technology.Additional details of chamber 100 or methods performed may be describedfurther below. Chamber 100 may be utilized to form film layers accordingto some embodiments of the present technology, although it is to beunderstood that the methods may similarly be performed in any chamberwithin which film formation may occur. The processing chamber 100 mayinclude a chamber body 102, a substrate support 104 disposed inside thechamber body 102, and a lid assembly 106 coupled with the chamber body102 and enclosing the substrate support 104 in a processing volume 120.A substrate 103 may be provided to the processing volume 120 through anopening 126, which may be conventionally sealed for processing using aslit valve or door. The substrate 103 may be seated on a surface 105 ofthe substrate support during processing. The substrate support 104 maybe rotatable, as indicated by the arrow 145, along an axis 147, where ashaft 144 of the substrate support 104 may be located. Alternatively,the substrate support 104 may be lifted up to rotate as necessary duringa deposition process.

A plasma profile modulator 111 may be disposed in the processing chamber100 to control plasma distribution across the substrate 103 disposed onthe substrate support 104. The plasma profile modulator 111 may includea first electrode 108 that may be disposed adjacent to the chamber body102, and may separate the chamber body 102 from other components of thelid assembly 106. The first electrode 108 may be part of the lidassembly 106, or may be a separate sidewall electrode. The firstelectrode 108 may be an annular or ring-like member, and may be a ringelectrode. The first electrode 108 may be a continuous loop around acircumference of the processing chamber 100 surrounding the processingvolume 120, or may be discontinuous at selected locations if desired.The first electrode 108 may also be a perforated electrode, such as aperforated ring or a mesh electrode, or may be a plate electrode, suchas, for example, a secondary gas distributor.

One or more isolators 110 a, 110 b, which may be a dielectric materialsuch as a ceramic or metal oxide, for example aluminum oxide and/oraluminum nitride, may contact the first electrode 108 and separate thefirst electrode 108 electrically and thermally from a gas distributor112 and from the chamber body 102. The gas distributor 112 may defineapertures 118 for distributing process precursors into the processingvolume 120. The gas distributor 112 may be coupled with a first sourceof electric power 142, such as an RF generator, RF power source, DCpower source, pulsed DC power source, pulsed RF power source, or anyother power source that may be coupled with the processing chamber. Insome embodiments, the first source of electric power 142 may be an RFpower source.

The gas distributor 112 may be a conductive gas distributor or anon-conductive gas distributor. The gas distributor 112 may also beformed of conductive and non-conductive components. For example, a bodyof the gas distributor 112 may be conductive while a face plate of thegas distributor 112 may be non-conductive. The gas distributor 112 maybe powered, such as by the first source of electric power 142 as shownin FIG. 1, or the gas distributor 112 may be coupled with ground in someembodiments.

The first electrode 108 may be coupled with a first tuning circuit 128that may control a ground pathway of the processing chamber 100. Thefirst tuning circuit 128 may include a first electronic sensor 130 and afirst electronic controller 134. The first electronic controller 134 maybe or include a variable capacitor or other circuit elements. The firsttuning circuit 128 may be or include one or more inductors 132. Thefirst tuning circuit 128 may be any circuit that enables variable orcontrollable impedance under the plasma conditions present in theprocessing volume 120 during processing. In some embodiments asillustrated, the first tuning circuit 128 may include a first circuitleg and a second circuit leg coupled in parallel between ground and thefirst electronic sensor 130. The first circuit leg may include a firstinductor 132A. The second circuit leg may include a second inductor 132Bcoupled in series with the first electronic controller 134. The secondinductor 132B may be disposed between the first electronic controller134 and a node connecting both the first and second circuit legs to thefirst electronic sensor 130. The first electronic sensor 130 may be avoltage or current sensor and may be coupled with the first electroniccontroller 134, which may afford a degree of closed-loop control ofplasma conditions inside the processing volume 120.

A second electrode 122 may be coupled with the substrate support 104.The second electrode 122 may be embedded within the substrate support104 or coupled with a surface of the substrate support 104. The secondelectrode 122 may be a plate, a perforated plate, a mesh, a wire screen,or any other distributed arrangement of conductive elements. The secondelectrode 122 may be a tuning electrode, and may be coupled with asecond tuning circuit 136 by a conduit 146, for example a cable having aselected resistance, such as 50 ohms, for example, disposed in the shaft144 of the substrate support 104. The second tuning circuit 136 may havea second electronic sensor 138 and a second electronic controller 140,which may be a second variable capacitor. The second electronic sensor138 may be a voltage or current sensor, and may be coupled with thesecond electronic controller 140 to provide further control over plasmaconditions in the processing volume 120.

A third electrode 124, which may be a bias electrode and/or anelectrostatic chucking electrode, may be coupled with the substratesupport 104. The third electrode may be coupled with a second source ofelectric power 150 through a filter 148, which may be an impedancematching circuit. The second source of electric power 150 may be DCpower, pulsed DC power, RF bias power, a pulsed RF source or bias power,or a combination of these or other power sources. In some embodiments,the second source of electric power 150 may be an RF bias power.

The shaft 144 of the substrate support 104 of FIG. 1 may further includea purge line 155 disposed at a distance 165 from the backside ofsubstrate support 104. A gas may be fed to the substrate support 104through purge line 155 from a gas supply 170. Additional details ofpurge line 155 or methods performed may be described further below.

The lid assembly 106 and substrate support 104 of FIG. 1 may be usedwith any processing chamber for plasma or thermal processing. Inoperation, the processing chamber 100 may afford real-time control ofplasma conditions in the processing volume 120. The substrate 103 may bedisposed on the substrate support 104, and process gases may be flowedthrough the lid assembly 106 using an inlet 114 according to any desiredflow plan. Gases may exit the processing chamber 100 through an outlet152. Electric power may be coupled with the gas distributor 112 toestablish a plasma in the processing volume 120. The substrate may besubjected to an electrical bias using the third electrode 124 in someembodiments.

Upon energizing a plasma in the processing volume 120, a potentialdifference may be established between the plasma and the first electrode108. A potential difference may also be established between the plasmaand the second electrode 122. The electronic controllers 134, 140 maythen be used to adjust the flow properties of the ground pathsrepresented by the two tuning circuits 128 and 136. A set point may bedelivered to the first tuning circuit 128 and the second tuning circuit136 to provide independent control of deposition rate and of plasmadensity uniformity from center to edge. In embodiments where theelectronic controllers may both be variable capacitors, the electronicsensors may adjust the variable capacitors to maximize deposition rateand minimize thickness non-uniformity independently.

Each of the tuning circuits 128, 136 may have a variable impedance thatmay be adjusted using the respective electronic controllers 134, 140.Where the electronic controllers 134, 140 are variable capacitors, thecapacitance range of each of the variable capacitors, and theinductances of the first inductor 132A and the second inductor 132B, maybe chosen to provide an impedance range. This range may depend on thefrequency and voltage characteristics of the plasma, which may have aminimum in the capacitance range of each variable capacitor. Hence, whenthe capacitance of the first electronic controller 134 is at a minimumor maximum, impedance of the first tuning circuit 128 may be high,resulting in a plasma shape that has a minimum aerial or lateralcoverage over the substrate support. When the capacitance of the firstelectronic controller 134 approaches a value that minimizes theimpedance of the first tuning circuit 128, the aerial coverage of theplasma may grow to a maximum, effectively covering the entire workingarea of the substrate support 104. As the capacitance of the firstelectronic controller 134 deviates from the minimum impedance setting,the plasma shape may shrink from the chamber walls and aerial coverageof the substrate support may decline. The second electronic controller140 may have a similar effect, increasing and decreasing aerial coverageof the plasma over the substrate support as the capacitance of thesecond electronic controller 140 may be changed.

The electronic sensors 130, 138 may be used to tune the respectivecircuits 128, 136 in a closed loop. A set point for current or voltage,depending on the type of sensor used, may be installed in each sensor,and the sensor may be provided with control software that determines anadjustment to each respective electronic controller 134, 140 to minimizedeviation from the set point. Consequently, a plasma shape may beselected and dynamically controlled during processing. It is to beunderstood that, while the foregoing discussion is based on electroniccontrollers 134, 140, which may be variable capacitors, any electroniccomponent with adjustable characteristic may be used to provide tuningcircuits 128 and 136 with adjustable impedance.

FIG. 2 shows exemplary operations in a temperature modulation method 200according to some embodiments of the present technology. The method maybe performed in a variety of processing chambers, including processingchamber 100 described above. Method 200 may include a number of optionaloperations, which may or may not be specifically associated with someembodiments of methods according to the present technology. For example,many of the operations are described in order to provide a broader scopeof the structural formation, but are not critical to the technology, ormay be performed by alternative methodology as would be readilyappreciated. Method 200 may describe operations shown schematically inFIGS. 3 and 5A-5E, the illustrations of which will be described inconjunction with the operations of method 200. It is to be understoodthat the figures illustrate only partial schematic views, and asubstrate may contain any number of additional materials and featureshaving a variety of characteristics and aspects as illustrated in thefigures.

Method 200 may include additional operations prior to initiation of thelisted operations. For example, additional processing operations mayinclude forming structures on a semiconductor substrate, which mayinclude both forming and removing material. Prior processing operationsmay be performed in the chamber in which method 200 may be performed, orprocessing may be performed in one or more other processing chambersprior to delivering the substrate into the semiconductor processingchamber in which method 200 may be performed. Regardless, method 200 mayoptionally include delivering a semiconductor substrate to a processingregion of a semiconductor processing chamber, such as processing chamber100 described above, or other chambers that may include one or morecomponents as described above. The substrate 103 may be deposited on asubstrate support, which may be a pedestal such as substrate support104, and which may reside in a processing region of the chamber, such asprocessing volume 120 described above. An exemplary substrate 303 isillustrated in FIG. 3 on substrate support 304 for substrate/supportsystem 300.

The substrate support 304 may be any number of materials on whichsubstrates may be disposed. The substrate support may be or include aceramic material, for example oxides or nitrides. Suitable oxides may beor include aluminum oxide and suitable nitrides may be or includealuminum nitride or silicon nitride, and may further include metalmaterials, or any number of combinations of these materials, which maybe the substrate support 304, or materials formed within or on substratesupport 304. In some embodiments, substrate support 304 may includeelectrodes and/or heating elements embedded within the substrate support304 for holding substrate 303. For example, as shown in FIG. 3,substrate support 304 may be embedded with electrode 322 and heatingelement 324. Electrode 322 may be coupled via conduit 182 to RF line 180and heating element 324 may be coupled via conduit 192 to AC line 190.Substrate support 304 may include a substrate support surface 304 a anda backside surface 304 b opposite substrate support surface 304 a. Acircumferential edge 304 c may connect substrate support surface 304 aand backside surface 304 b. A central axis 147 may extend throughsubstrate support 304. The substrate support 304 may be rotatable alongaxis 147 and hermetically sealed to shaft 344.

At optional operation 205, such as during development of the pedestal orconfiguration within the chamber, a purge line 155 may be providedwithin shaft 344 and extending within substrate support 304. A gas maybe flowed through purge line 155, which may direct the gas to thebackside surface 304 b. Purge line 155 may have a first end 162 and mayinclude a nozzle 160 at the first end 162. In some embodiments athermocouple may be disposed within the purge line. The purge line 155may be or include a flexible material or a rigid material. The purgeline may be or include a material chosen from stainless steel, aluminum,nylon, or combinations thereof, and rigidity provided may afford a morespecific direction of flow, allowing a specific impingement of gas on aparticular region of the backside of the puck. At optional operation210, the first end 162 of purge line 155 may be set at a first distance165 from the backside surface 304 b of substrate support 304 to allowflow of gas to the backside 304 b of substrate support 304. The distance165 may be fixed by a bracket, which may be coupled to the shafthousing, or additional conduits extending through the shaft. Forexample, the first end 162 of purge line 155 may be fixed less than orabout 3 mm from backside 304 b of substrate support 304, less than orabout 2 mm, less than or about 1 mm, or less. The distance of offset ofthe purge line may affect the size of a region of impact on the backsideof the pedestal, which may determine a zone of affected temperaturethrough the structure and substrate.

Some embodiments of the present technology may include setting a purgeline nozzle 160 diameter at optional operation 215. Nozzle 160 may beadjustable to project a spray at varying trajectories. In someembodiments, the nozzle 160 may be adjusted to direct the gas to a firstportion of the substrate support, the first portion having a firstdiameter d₁. In some embodiments, the nozzle 160 may be adjusted todirect the gas to a second portion of the substrate support, the secondportion having a second diameter d₂. The diameter may be set to anynumber of settings continuously or incrementally to refine thetemperature modulation of the substrate support 304, and the modulationmay occur during processing in some embodiments.

Some embodiments of the present technology may include flowing a gasthrough the purge line 155 at operation 220. The gas may be deliveredfrom a gas supply 170 and directed along axis 147 extending to first end162 and out nozzle 160. The gas may be delivered or driven and maytravel along a flow pathway 175. The gas may flow convectively such thatthe heat transfer of the gas may include the circulation of currents,represented by flow pathway 175. The flow pathway 175 may provide thatthe gas moves from gas supply 170 through the purge line 155 and towardthe backside 304 b of substrate support 304. The flow pathway 175 mayprovide that the gas then removes heat and exits through the shaft. Thegas may be a high thermal conductivity gas. In some embodiments, the gasis chosen from at least one of helium, nitrogen, argon, and combinationsthereof. Selection of a precursor may be performed based on a variety ofvariables. For example, although helium may be relatively more expensivethan nitrogen or argon, the smaller molecule gas may provide improvedheat transfer for a given volume delivered. Relatedly, nitrogen andargon may allow higher flow rates to be delivered as gas utilization maybe more affordable, and velocity of delivery may provide an additionalvariable for tuning. The gas may be supplied to the purge line 155 atroom temperature. Alternatively, delivering the gas may includesupplying a preheated gas to the purge line 155 from gas supply 170.

For example, depending on the gas used, gas may be delivered to thepurge line 155 at a flow rate less than or about 50 sccm, and may bedelivered at a flow rate less than or about 40 sccm, less than or about30 sccm, less than or about 20 sccm, less than or about 10 sccm, lessthan or about 9 sccm, less than or about 8 sccm, less than or about 7sccm, less than or about 6 sccm, less than or about 5 sccm, or less.Similarly, helium, nitrogen, argon, or any other gas may be delivered tothe purge line 155 at a flow rate less than or about 1,000 sccm, and maybe delivered at a flow rate less than or about 800 sccm, less than orabout 600 sccm, less than or about 500 sccm, less than or about 450sccm, less than or about 400 sccm, less than or about 350 sccm, lessthan or about 300 sccm, less than or about 250 sccm, less than or about200 sccm, or less. Any additional ranges within these ranges or ascombinations of any stated or unstated number may also be used.

At operation 225, temperature modulation may be adjusted or fine-tunedto achieve a desired substrate support temperature profile, such asprofiles shown schematically in FIGS. 5B-5E. In some embodiments,adjusting may include at least one of adjusting the gas flow rate andthe nozzle diameter. For example, the gas flow rate may be increased forincreased removal of heat to lower the substrate support 304 temperatureor to effect a temperature reduction of the substrate supporttemperature profile at a region of impingement, and the gas flow ratemay be decreased for decreased removal of heat to allow the substratesupport temperature to rise. Nozzle 160 may be adjusted to direct thegas to at least a first or second portion of the substrate support, andthe portions may be characterized as having different diameters, whichmay affect a smaller or larger area of the substrate support as needed.Adjusting the at least one of adjusting the gas flow rate and the nozzlediameter may be repeated as needed until the desired substrate supporttemperature profile is achieved. At optional operation 230, the gas flowmay be halted. The gas flow may be stopped when a desired outcome isattained such a uniform film thickness is deposited onto the substratethe end of a deposition process, or the gas flow may be stopped when adesired substrate support temperature profile is attained. The stoppageof gas flow may be initiated by reducing the flow rate of the gas tozero, or by closing the nozzle 160 such as by closing a nozzle aperture,or by closing the gas feed from gas supply 170, or by a combinationthereof.

The temperature modulation method for a semiconductor substrate supportof the present technology may result in a more uniform film depositedacross a diameter of the substrate 303. In some embodiments, anormalized thickness, which may be produced at any specific filmthickness, may be within less than or about 0.015, less than or about0.010, less than or about 0.005, or less, from a highest, a lowest, oran average thickness of any location across the substrate. As acomparative example, as shown in FIG. 4, a conventional substratesupport had a substrate disposed thereon, which was deposited with afilm. The conventional substrate support had a non-uniform temperatureprofile where the central portion 405 of the substrate support, as wellas the substrate support edges 410, exhibited a higher temperature. Theresultant film thickness was also non-uniform with a thicker filmthickness (normalized) corresponding to the central portion 405 andedges 410.

As illustrated schematically in FIG. 5A, gas 570 may be delivered tosubstrate 504 having a center 505A and edges 510A. The gas 570 may bedelivered from a purge line as previously described. In some embodimentsof modulation according to aspects of the present technology, a desiredsubstrate support temperature profile may be achieved, non-limitingexamples of which are shown in FIGS. 5B-5E. The example of FIG. 5B showsa substrate support temperature profile having a central portion 505Bwhere the temperature may be lowest and gradually increases toward edges510B. The example of FIG. 5C shows a substrate support temperatureprofile having a central portion 505C where the temperature may beconstant extending through mid-regions of the substrate, and which maybe lower than at the edges 510C. The example of FIG. 5D shows asubstrate support temperature profile having a center 505D of acontrolled profile where the temperature may be lower than at the edges510D, but may be more controlled than a proportional change intemperature relative to distance, such as with profile illustrated inFIG. 5B, for example. Similarly, the example of FIG. 5E shows asubstrate support temperature profile having a center 505E where agenerally controlled profile extends from the center 505E having thelowest temperature gradually increasing to the edges 510E. It is to beunderstood that the temperature profiles illustrated in FIGS. 5B-5E arenot intended to limit the present technology, but merely provideexamples of gas delivery affects that may provide control overtemperature, and thus deposition, across exemplary substrates.

The substrate support temperature may be maintained above or about 100°C. during a deposition process, and may be maintained at a temperatureof greater than or about 120° C., greater than or about 140° C., greaterthan or about 160° C., greater than or about 180° C., greater than orabout 200° C., greater than or about 220° C., greater than or about 240°C., greater than or about 260° C., greater than or about 280° C.,greater than or about 300° C., greater than or about 320° C., greaterthan or about 340° C., greater than or about 360° C., greater than orabout 380° C., greater than or about 400° C., greater than or about 420°C., greater than or about 440° C., greater than or about 460° C.,greater than or about 480° C., greater than or about 500° C., orgreater. The temperatures of the substrate may additionally impact thesubstrate support temperature profile. For example, in some embodimentsthe substrate may be maintained at a temperature of greater than orabout 400° C., and may be maintained at a temperature of greater than orabout 420° C., greater than or about 440° C., greater than or about 460°C., greater than or about 480° C., greater than or about 500° C., orgreater.

A desired substrate support temperature profile may be one that producesa uniform temperature range during an operation such as a depositionprocess. In some embodiments, the uniform temperature range may be onethat deviates less than or about 5 degrees Celsius from the targetsubstrate support temperature, and may deviate less than or about 4degrees Celsius, less than or about 3 degrees Celsius, less than orabout 2 degrees Celsius, less than or about 1 degrees Celsius, less thanor about 0.5 degrees Celsius, or less. Additionally, the gas deliverymay allow a location at a surface of the substrate support on which thesubstrate may reside to be adjusted relative to any other location alongthe substrate, or may allow a gradient to be produced across the supportor substrate as described above. For example, a localized temperature,such as at a wafer center in line with a gas impingement position on thesupport, may be reduced relative to a position radially outward from thegas impingement location, such as at a half radius, edge location, orany other location, with a temperature range of less than or about 5°C., which may correspond to a similar reduction in temperature at a gasimpingement location on the substrate support, relative to a temperaturethroughout the rest of the support for example.

In some embodiments, the localized temperature may be controlled todeviate from other pedestal location temperatures by less than or about4° C., less than or about 3° C., less than or about 2° C., less than orabout 1° C., less than or about 0.8° C., less than or about 0.6° C.,less than or about 0.5° C., less than or about 0.4° C., less than orabout 0.3° C., less than or about 0.2° C., less than or about 0.1° C.,or less, depending on the desired temperature reduction. Similarly, atemperature gradient may be produced across the substrate supportcharacterized by any of the profiles discussed above, which may providea center to edge temperature difference, either linearly or along aparabolic or other profile, of less than or about 10° C., and mayprovide a temperature gradient of less than or about 10° C., less thanor about 10° C., less than or about 10° C., less than or about 10° C.,less than or about 10° C., less than or about 10° C., less than or about10° C., less than or about 10° C., less than or about 10° C., less thanor about 10° C., or less. Any smaller range encompassed by any of theseranges, and which may provide a specific central temperature reductionto reduce deposition in a particular location, such as at a centralregion, is similarly encompassed.

The gas delivery may also provide a temperature reduction of anytemperature stated or encompassed elsewhere at a range to positionedfrom a center of the substrate. For example, the temperature may bereduced by any temperature at a radius of less than or about 25 mm froma central axis through the substrate support, or gas delivery channel,and may be reduced at a location characterized by a radius from thecentral axis of less than or about 20mm, less than or about 15 mm, lessthan or about 10 mm, less than or about 9 mm, less than or about 8 mm,less than or about 7 mm, less than or about 6 mm, less than or about 5mm, less than or about 4 mm, less than or about 3 mm, less than or about2 mm, less than or about 1 mm, or less. By providing a centrallydelivered gas within the pedestal, center deposition profiles may becontrolled to provide more uniform deposition across a substrateaccording to embodiments of the present technology.

In the preceding description, for the purposes of explanation, numerousdetails have been set forth in order to provide an understanding ofvarious embodiments of the present technology. It will be apparent toone skilled in the art, however, that certain embodiments may bepracticed without some of these details, or with additional details.

Having disclosed several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theembodiments. Additionally, a number of well-known processes and elementshave not been described in order to avoid unnecessarily obscuring thepresent technology. Accordingly, the above description should not betaken as limiting the scope of the technology. Additionally, methods orprocesses may be described as sequential or in steps, but it is to beunderstood that the operations may be performed concurrently, or indifferent orders than listed.

Where a range of values is provided, it is understood that eachintervening value, to the smallest fraction of the unit of the lowerlimit, unless the context clearly dictates otherwise, between the upperand lower limits of that range is also specifically disclosed. Anynarrower range between any stated values or unstated intervening valuesin a stated range and any other stated or intervening value in thatstated range is encompassed. The upper and lower limits of those smallerranges may independently be included or excluded in the range, and eachrange where either, neither, or both limits are included in the smallerranges is also encompassed within the technology, subject to anyspecifically excluded limit in the stated range. Where the stated rangeincludes one or both of the limits, ranges excluding either or both ofthose included limits are also included.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural references unless the context clearly dictatesotherwise. Thus, for example, reference to “a gas” includes a pluralityof such precursors, and reference to “the layer” includes reference toone or more layers and equivalents thereof known to those skilled in theart, and so forth.

Also, the words “comprise(s)”, “comprising”, “contain(s)”, “containing”,“include(s)”, and “including”, when used in this specification and inthe following claims, are intended to specify the presence of statedfeatures, integers, components, or operations, but they do not precludethe presence or addition of one or more other features, integers,components, operations, acts, or groups.

1. A temperature modulation method for a semiconductor substrate supportcomprising: delivering a gas through a purge line extending within asubstrate support, the gas directed to a backside surface of thesubstrate support opposite a substrate support surface, wherein thepurge line extends along a central axis of a shaft, the shafthermetically sealed with the substrate support, wherein the substratesupport is characterized by a center and a circumferential edge, andwherein a first end of the purge line is fixed at a first distance fromthe backside surface of the substrate support; and flowing the gasconvectively at a first flow rate via a flow pathway to remove heat fromthe substrate support to achieve a desired substrate support temperatureprofile.
 2. The modulation method of claim 1, wherein flowing includesone of: increasing the first flow rate to a second flow rate to providea temperature reduction of the substrate support temperature profile;and decreasing the first flow rate to a second flow rate to provide atemperature increase of the substrate support temperature profile. 3.The modulation method of claim 1, wherein delivering the gas includesdelivering the gas through a nozzle at the first end of the purge line,the nozzle configured to direct the gas to a first portion of thebackside surface of the substrate support, wherein the first portion ischaracterized by a first diameter.
 4. The modulation method of claim 3,wherein the nozzle is adjustable to a second diameter to direct gas to asecond portion of the backside surface of the substrate support, whereinthe second portion is characterized by a second diameter different thanthe first diameter.
 5. The modulation method of claim 1, wherein asubstrate support temperature is maintained above or about 100° C.during a semiconductor process.
 6. The modulation method of claim 1,wherein the desired substrate support temperature profile includes auniform temperature range deviating by at most about 1 degree Celsius ata central location during a semiconductor process.
 7. The modulationmethod of claim 1, wherein the first end of the purge line is fixed atthe first distance from the backside surface of the substrate supportwith a bracket, and the first distance is at most about 3 mm.
 8. Themodulation method of claim 1, wherein the gas is a high thermalconductivity gas.
 9. The modulation method of claim 1, wherein the gasis chosen from at least one of helium, nitrogen, argon, and combinationsthereof
 10. The modulation method of claim 1, wherein delivering the gasincludes supplying the gas to the purge line at room temperature. 11.The modulation method of claim 1, wherein delivering the gas includessupplying a preheated gas to the purge line.
 12. A semiconductorprocessing chamber comprising: a substrate support having a substratesupport surface for contacting a substrate and characterized by acentral axis through the substrate support, a backside surface oppositethe substrate support surface, and a circumferential edge connecting thesubstrate support surface and the backside surface, the substratesupport disposed within a processing region of the semiconductorprocessing chamber; a shaft about the central axis and hermeticallysealed with the backside surface of the substrate support; a purge linedisposed concentrically within the shaft and about the central axis, thepurge line having a nozzle at a first end fixed at a first distance fromthe backside surface of the substrate support, the nozzle configured todeliver a high thermal conductivity gas to a first portion of thebackside surface of the substrate support, wherein the first portion ischaracterized by a first diameter; and a flow pathway configured tocontact the substrate support with the high thermal conductivity gas andexhaust the high thermal conductivity gas through the shaft to removeheat.
 13. The semiconductor processing chamber of claim 12, furthercomprising at least one of an RF line and an AC line.
 14. Thesemiconductor processing chamber of claim 12, wherein the nozzle isadjustable to deliver the high thermal conductivity gas to a secondportion of the backside surface of the substrate support, wherein thesecond portion is characterized by a second diameter different than thefirst diameter.
 15. The semiconductor processing chamber of claim 12,further comprising a gas supply configured to adjust the flow rate ofthe high thermal conductivity gas.
 16. The semiconductor processingchamber of claim 12, further comprising a thermocouple disposed withinthe purge line.
 17. The semiconductor processing chamber of claim 12,wherein the purge line comprises a flexible material or a rigidmaterial.
 18. The semiconductor processing chamber of claim 12, whereinthe purge line comprises a material chosen from stainless steel,aluminum, nylon, or combinations thereof
 19. The semiconductorprocessing chamber of claim 12, wherein the substrate support is aceramic material.
 20. The semiconductor processing chamber of claim 12,wherein the substrate support is aluminum nitride.